Reporting colorectal cancer.

Reporting colorectal cancer comprises two phases: the careful collection of pathological data; and the division of patients into groups with differing prognoses. Dukes' classification of rectal cancer was the outcome of this dual approach. It evolved over many years, and full details of its final form were not published until 1958, towards the end of his career. Others modified the classification during its evolution, and numerous rival pathological and clinicopathological systems now exist. The resulting confusion that surrounds the Dukes classification may make it impossible to compare pathological findings and the results of treatment between different centres. The importance of meticulous dissection and examination of surgical specimens is emphasised and a simple set of recommendations made. It is shown how modern statistical methods may identify pathological variables that have independent clinical importance. On the basis of this information a new system of prognostic categorisation for patients receiving apparently curative surgery for rectal cancer has been developed, which is superior to the Dukes classification in that it can place many more patients into groups with clear prognostic implications.